Simultaneous axially &amp; radially ignited caseless telescopic tube ammunition round

ABSTRACT

A caseless cartridge ammunition round occupying a minimum volume while yielding ballistic properties superior to comparable metal case rounds and comprising a completely telescopic projectile within a molded propellant cylinder, the round employing simultaneous radial and axial ignition.

ilnited States Patent [1 91 Quinlan et al.

451 May 15, 1973 SIMULTANEOUS AXIALLY & RADIALLY IGNITED CASELESS TELESCOPIC TUBE AMMUNITION ROUND Inventors: Joseph B. Quinlan; Earl F. Van Arstdalen, both of Philadelphia, Pa.

Assignee: The United States of America as represented by the Secretary of the Army Filed: Mar. 23, 1971 Appl. No.: 127,296

US. Cl. ..l02/40, 102/44, 102/45,

102/DIG. 1 Int. Cl ..F42b 5/16 Field of Search ..l02/38, 39, 40, DIG. 1

[56] References Cited UNITED STATES PATENTS 3,482,516 12/1969 Farmer et a1 ..lO2/38 3,557,700 1/1971 Quinlan ....l02/38 3,009,419 11/1961 Clay, Jr. et al. ....102/46 3,575,112 4/1971 Farmer ....102/38 3,439,635 4/1906 Hensley 102/38 3,345,945 10/1967 Quinlan et al. ..l02/38 Primary Examiner-Robert F. Stahl Attorney- Harry M. Saragovitz, Edward J. Kelly, Herbert Berl & Sheldon Kanars [57] ABSTRACT A caseless cartridge ammunition round occupying a minimum volume while yielding ballistic properties superior to comparable metal case rounds and comprising a completely telescopic projectile within a molded propellant cylinder, the round employing simultaneous radial and axial ignition.

5 Claims, 3 Drawing Figures SIMULTANEOUS AJGALLY & RADIALLY IGNITED CASELESS TELESCOPIC TUBE AMMUNITION ROUND The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to us of any royalty thereon.

This invention relates to ammunition rounds and more particularly, concerns telescoped caseless cartridges which embody simultaneous radial and axial ignition.

The principal object of this invention is to provide a caseless cartridge occupying a minimum volume while yet possessing superior ballistic properties.

Other objects and advantages of the invention will become apparent from the following description and accompanying drawings wherein:

FIG. 1 illustrates a sectional view of a round embodying the principles of our invention; and

FIGS. 2 and 3 illustrate a top and side view respectively of propellant plug 30 shown in FIG. 1. Referring now to the drawings, our cartridge has an outer propellant cylinder which is suitably molded and comprises a single base extruded grain propellant, 100 percent nitrocellulose modified with minor amounts of a stabilizer, such as diphenylamine, for example; a deterrent, such as dibutylphthalate, for example; and a flash suppressor, such as potassium sulfate, for example, the actual composition of outer propellant cylinder 10 forming no part of this invention.

The entire length of cylinder 10 is lined with a propellant support or guide tube 12 which comprises a double base propellant, the nitroglycerin thereof falling within the range of about 38 42 percent. Again, small amounts of selected modifiers will be present, such, for example, as diphenylamine, dibutylphthalate, and the like. Support tube 12 is bonded to outer propellant cylinder 10 with a nitrocellulose adhesive, suitably dissolved in a mixture of ethanol-acetone, of roughly 50-50 proportions. Other suitable energetic lacquers may be used advantageously.

Support tube 12 positions and aligns projectile 14, having a rotating band 16. Projectile 14 is completely telescoped within cylinder 10 and tube 12 and may vary in size from about mm to 90mm.

Located below projectile 14 is our ignition assembly, which includes a lower propellant cylinder 20 comprising identically or substantially the composition of outer propellant cylinder 10, and is open at both ends, its upper end contacting the lower portions of projectile 14, and its lower portion being coextensive with outer propellant cylinder 10 and support tube 12. Disposed within lower propellant cylinder 20 is inner propellant cylinder 22, made of the same propellant composition as lower propellant cylinder 20. Its bottom end only is open however for receiving lead styphnate type explosive pellets 24 and plug 26, the latter retaining pellets 24 in position thereabove and also providing rapid igni tion from primer 28 and booster 30, due to the nature of its pure nitrocellulose composition.

The primer and booster are essentially of the same composition as that of the outer propellant cylinder 10 but will possess a smaller web and therefore be faster burning grains. The explosive pellet comprising the primer and booster will preferably be of the lead styphnate type. Both primer and booster are enclosed by the lower propellant cylinder and will be placed immediately below inner propellant cylinder 22.'The cylinders 20 and 22 are bonded with a nitrocellulose adhesive,

similar to'that used in bonding outer propellant cylinder 10 to guide tube 12.

Surrounding lower propellant cylinder 20 at its lower portions is a propellant plug 31, which is bonded to both lower propellant cylinder 20 and guide tube 12 with the nitrocellulose adhesive aforedescribed, the plug permitting radial ignition substantially simultaneously with axial ignition through pellets 24. Propellant plug 31 is shown in detail in FIGS. 2 and 3 and comprises a composition identical with outer propellant cylinder 10 and has a plurality of passageways 32 communicating from its periphery to its central portions where it is bonded to cylinder 20. Within each passageway is disposed a nitrocellulose fiber plug 34 for providing rapid ignition from cylinder 20 to explosive pellets 36 disposed outwardly of plugs 34 in passageways 32.

A mica seal or disc 40 is attached or bonded to the base of the cartridge as shown to provide thermal protection to the bolt and firing pin (not shown) as well as erosive protection thereto.

Above plug 31 is free volume 42 which performs its usual function in our ignition system. When the firing pin impacts primer 28 after penetrating mica seal 40, the primer and booster are sequentially ignited which sets ofi' an axial ignition train through plugs 34 and pellets 36. The radial ignition occurs simultaneously along each of the 4 passageways 32 located in propellant plug 31. Gas thus formed from ignition of plugs and pellets and the lower and inner propellant cylinders together with guide tube and outer propellantcylinder push the projectile forward. The ignition of the cylinder 10 and tube 12 will coincide with the ignition of cylinders 20 and 22 to effect optimum velocity of the projectile.

We wish it to be understood that we do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

We claim:

1. A telescoped caseless ammunition cartridge comprising an outer propellant cylinder,

a projectile completely telescoped within said cylinder,

an ignition assembly behind said cylinder,

a mica disc or seal bonded to said ignition assembly at its rearrnost portion for minimizing thermal and abrasive erosion to a firing pin and bolt assembly upon ignition of said ignition assembly,

said ignition assembly comprising an open ended lower propellant cylinder communicating between said mica seal and said projectile,

an inner propellant cylinder axially aligned within and bonded to said lower propellant cylinder and having a closed upper end and an open lower end,

a first set of explosive pellets disposed within said inner propellant cylinder,

5 a propellant plug surrounding a lower portion of said lower propellant plug, said plug containing a plurality of spaced passageways communicating between said guide tube and said lower propellant cylinder, said lower propellant cylinder and said guide tube providing a free air space thereinbetween and above said propellant plug,

interiorly said second set of pellets.

4. The cartridge of claim 1 further characterized by said outer, lower and inner propellant cylinders and said propellant plug being a single base extruded propellant, said guide tube being a double base propellant having a nitroglycerine content ranging between about 38 42 weight percent, and said pellets being of the type lead styphnate.

5. The cartridge as described in claim 1 wherein said igniting means consists of a primer and booster. 

1. A telescoped caseless ammunition cartridge comprising an outer propellant cylinder, a projectile completely telescoped within said cylinder, an ignition assembly behind said cylinder, a mica disc or seal bonded to said ignition assembly at its rearmost portion for minimizing thermal and abrasive erosion to a firing pin and bolt assembly upon ignition of said ignition assembly, said ignition assembly comprising an open ended lower propellant cylinder communicating between said mica seal and said projectile, an inner propellant cylinder axially aligned within and bonded to said lower propellant cylinder and having a closed upper end and an open lower end, a first set of explosive pellets disposed within said inner propellant cylinder, a propellant plug surrounding a lower portion of said lower propellant plug, said plug containing a plurality of spaced passageways communicating between said guide tube and said lower propellant cylinder, said lower propellant cylinder and said guide tube providing a free air space thereinbetween and above said propellant plug, a second set of explosive pellets disposed within said passageways, and means within said lower propellant cylinder and below said first set of pellets for igniting each of said first and second set of pellets for providing axial and radial ignition to said cartridge.
 2. The cartridge of claim 1 wherein a nitrocellulose plug is disposed below said first set of explosive pellets and above said igniting means.
 3. The cartridge of claim 1 wherein another nitrocellulose plug is disposed within each of said passageways interiorly said second set of pellets.
 4. The cartridge of claim 1 further characterized by said outer, lower and inner propellant cylinders and said propellant plug being a single base extruded propellant, said guide tube being a double base propellant having a nitroglycerine content ranging between about 38 - 42 weight percent, and said pellets being of the type lead styphnate.
 5. The cartridge as described in claim 1 wherein said igniting means consists of a primer and booster. 